Joe is correct.  NMEA0183 is not RS232.  I think it is RS422, but am not
sure.  It might be RS485.  At any rate, they often play well together, but
not always.  You can purchase RS422 and RS485 converters for USB.

Gary

~~~~~~~_/)~~~~~~


On Fri, Sep 16, 2016 at 7:42 AM, Della Barba, Joe via CnC-List <
cnc-list@cnc-list.com> wrote:

> To make matters even worse, a lot of devices you THINK are USB devices
> have the converter chip inside them somewhere and have the same issues,
> with the drawback that you can’t change it.
>
> See any number of cheap interface cables for OBD car diagnostics. I think
> I have 2 or 3 that won’t reliably connect.
>
> Also note NMEA 0183 and RS-232 are not the same voltage specifications.
> Well over 90% of the time they play well together, but not 100%. I had a
> non-marine GPS puck that had an RS-232 serial connection. It worked OK for
> just the laptop, but failed driving the laptop, the VHF, and the APRS
> tracker. I had to buy a marine Garmin unit that had a true buffered NMEA
> output with enough power to deal with multiple listeners.
>
> Joe
>
> Coquina
>
>
>
> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *Marek
> Dziedzic via CnC-List
> *Sent:* Thursday, September 15, 2016 10:39 PM
> *To:* cnc-list@cnc-list.com
> *Cc:* Marek Dziedzic
> *Subject:* Re: Stus-List USB to Serial - reading NMEA stream
>
>
>
> Dennis,
>
>
>
> I cannot answer any of the really technical questions, but…
>
>
>
> There is, generally, a problem with eth USB2Serial adapters. One of the
> most common is that the adapter does not have the real Prolific h/w; rather
> is an imitation. This happens even if you purchased the adapter from a
> reputable source. This is a reasonably well know issue. To the point that
> some s/w developers refuse to support a solution if a USB2Serial adapter is
> used. I had major stability problem with my previous weather station that
> used a serial connection and a special rain dance or waving a chicken leg
> was often required in order to make it connect.
>
>
>
> So, in short, there may not be a bullet proof USB2Serial driver.
>
>
>
> Marek
>
> Ottawa, ON
>
>
>
>
>
>
>
> *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com
> <cnc-list-boun...@cnc-list.com>] *On Behalf Of *Dennis C. via CnC-List
> *Sent:* Thursday, September 15, 2016 17:26
> *To:* CnClist <CnC-List@cnc-list.com>
> *Cc:* Dennis C. <capt...@gmail.com>
> *Subject:* Stus-List USB to Serial - reading NMEA stream
>
>
>
> Really technical question here.
>
>
> I'm try to solve a puzzling issue on Touche'.  I installed a Noland AM43
> multiplexer to gather wind data from my Nexus instruments and send it to my
> Simrad WP30 wheel pilot.  That works now.  However, in the process, the
> WP30 is not receiving the waypoint arrival alarm.  When the WP30 was
> interfaced directly to the GPS, it always deactivated "Nav" mode when we
> got to 0.10 nm of a waypoint and the arrival alarm activated.  Now I hear
> the GPS audible alarm but the WP30 keeps on steering.
>
> I know the WP30 is receiving GPS data because it steers right past the
> waypoint and gradually changes course and navigates dutifully to the next
> waypoint in the route.  The Nexus instruments show all the correct data,
> distance/bearing to waypoint, course to steer, cross track error, etc.
>
>
>
> I have what I consider the appropriate sentences programmed into the Nexus
> NMEA output slots; APA, APB, RMB, etc.
>
> I want to read and log the data stream.  The AM43 has a USB port.
>
> I have a Dell mini laptop with a Prolific PL2303 USB to Serial driver
> installed. It usually shows on COM3.  I have two applications, GPSinfo and
> DPort Lite (a lite version of Hyperterminal).  I can see the NMEA data
> stream from my Globalsat BU-353 GPS adapter on both applications but I have
> to unplug and re-plug the BU-353 in some mystical order for it to be seen
> in DPort Lite.
>
> Since there is no Wi-Fi or internet at my marina for troubleshooting, I
> want some reasonable assurance that when I connect to the multiplexer, I
> will see data.  I two questions for the cyber-minded folks.
>
> 1.  Is there a bombproof USB serial driver that will work every time with
> DPort Lite without having to plug/unplug/reboot or place a chicken wing
> under a cypress tree at full moon?
>
> 2.  Where in the APA, APB, RMB sentences is the arrival alarm data and
> what characters signal on or off?
>
> Thanks,
>
> Dennis C.
>
> Touche' 35-1 #83
>
> Mandeville, LA
>
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